You can delete any IMAP and Exchange accounts before trying to export. this would leave only "On My Computer" data. Work off a copy of your Identity!!
The only thing I really care about (and it isn't a terribly high priority) is the mail and there are possibly some contacts in there...
If you are hoping to recover the the hidden autofil contacts, these do not export. However, they are saved in Data Records folder. Look for Recent Addresses.
You can create a new Identity and drag over the folder "Recent Addresses" then rebuild the Identity. I would duplicate this in case you need it for further testing. Import your .olm files into an Identity that has the recent addresses.
Autofil , Autocomplete or Most Recently Used (MRU)
These entries are not in the AddressBook.
AutoComplete feature gathers addresses from both the address book and the recently-used list (with a maximum of 200 entries). They are sorted intelligently, organized by the frequency of messaging for each contact, with the most-used contacts showing up on top.
There will always be 200. Some will always be considered "useless" by the user. The better organized you are at adding "good" addresses to you address book the more you will enjoy the MRU feature.
Don't rely on this list as a substitute for adding contacts to the AddressBook.